This invention relates to a process for the heat sterilization of materials, such as, foodstuffs, cosmetics, pharmaceuticals, articles of manufacture, and components thereof, which are vulnerable to change or degradation at the elevated temperatures needed to achieve sterilization. For example, the process can be used to sterilize antibiotics, such as aminoglycosides, specifically tobramycin and gentamicin. Under such conditions of elevated temperature, the oxidative effects of ambient atmospheric oxygen can be destructive of the materials under study, also destructive can be the interaction of volatiles rising from the material and resulting surface reactions with the material being sterilized. Of course, "destructive` in this sense includes mere surface changes which are not obvious on gross examination, but which in the realm of pharmaceuticals and foodstuffs, for example, would be intolerable.
The art has traditionally employed heat sterilization of materials of the kind enumerated above, and at times has been oblivious to the subtle effects of degradation or change, or has discovered that the resulting changes have not altered the intended utility after the sterilization to an extent sufficient to compel an alternative form of sterilization. Such decisions, obviously, are decided on a case by case basis. One art area, however, which elected to forego any attempt at heat sterilization of materials labile to oxidative degradation is the pharmaceutical field because of the requirements of health regulatory authorities and more fundamental concerns that the final product stay within the originally stated specifications. Thus, for sterilization of pharmaceuticals labile to oxidation, the industry relies on techniques of sterile filtration, sterile manufacture or compounding of sterile components. Of course, heat sterilization of certain final product forms can be performed by heating, provided thermal degradation or hydrolysis is not a factor, by virtue of the protection afforded the oxygen-labile active via its pharmaceutical form or vehicle, e.g., sealed solutions, ointments, and tablets. But heat sterilization of bulk actives labile to degradative changes of the kind discussed above has heretofore been precluded as an industrial process.